A judge has ruled that a marriage counsellor must give evidence in the Supreme Court murder trial of Brisbane man Gerard Baden-Clay.

He has pleaded not guilty to murdering his wife Allison Baden-Clay and interfering with her corpse in April last year.

The body of the 43-year-old mother-of-three was found under a bridge at Kholo Creek in Brisbane's western suburbs 10 days after she went missing from the family's Brookfield home.

Gerard Baden-Clay's trial is scheduled to begin in June next year.

Relationships Australia marriage counsellor Carmel Ritchie held sessions with the pair, but did not want to give evidence at the trial.

Ms Ritchie's lawyer had argued the sessions were protected under the Family Law Act, and breaching their confidentiality would discourage others from seeking counselling.

Supreme Court Justice James Douglas has dismissed that argument, ruling the evidence - including notes from the counselling sessions - must be provided.

In a written decision handed down today, Justice Douglas said: "Even if such a privilege existed separate from the Act, the balance is decisively in favour of permitting access to the evidence for the purposes of Mr Baden-Clay’s trial on the charge of murder."

"The counsellor is required to give evidence at the preliminary hearing including evidence of anything said or any admission made to her by the deceased Allison Baden-Clay or the defendant Gerard Baden-Clay."